Critical Care

, 14:P482 | Cite as

Adding ultralow-dose oral naltrexone to morphine: a double-blind, randomized clinical trial

  • S Farahmand
  • O Ahmadi
Poster presentation


Morphine Naltrexone Opioid Analgesia Pain Rating Opioid Antagonist 
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Ultralow-dose opioid antagonists can enhance opioid analgesia and prevent tolerance in rodent nociceptive pain assays.


A randomized, double-blind controlled trial is designed to investigate whether the addition of 5 ml ultralow-dose naltrexone (1 μg in a liter of sterile water) to morphine (0.05 mg/kg) changes the total opioid requirement and side effects.


Two hundred and sixty-seven patients (18 to 45 years old) with moderate extremities trauma entered the study, Pain control measurements were evaluated every 15 minutes for the first hour, then every 30 minutes for the second and third hours and finally at the fourth hour. Efficacy was measured by the 11-point numerical pain rating scale. The following side effects were evaluated: sedation, nausea, vomiting and pruritus. We found that opioid requirements did not differ significantly between groups. The morphine + naltrexone group on average required 0.04 mg more morphine during the 4 hours than the morphine group.


The morphine + naltrexone group had a lower incidence of nausea than the morphine + placebo group. However, the incidence of vomiting, pruritus and sedation between the two groups were similar. The combination of ultralow-dose naltrexone and morphine in moderate extremities trauma did not affect opioid requirements, but it decreased the incidence of nausea.


  1. 1.
    Crain SM, Shen KF: Antagonists of excitatory opioid receptor functions enhance morphine's analgesic potency and attenuate opioid tolerance/dependence liability. Pain 2000, 84: 121-131. 10.1016/S0304-3959(99)00223-7PubMedCrossRefGoogle Scholar
  2. 2.
    Cepeda MS, Africano JM, Manrique AM, Fragoso W, Carr DB: The combination of low dose of naloxone and morphine in PCA does not decrease opioid requirements in the postoperative period. Pain 2002, 96: 73-79. 10.1016/S0304-3959(01)00425-0PubMedCrossRefGoogle Scholar

Copyright information

© BioMed Central Ltd. 2010

Authors and Affiliations

  • S Farahmand
    • 1
  • O Ahmadi
    • 2
  1. 1.Tehran University of Medical SciencesTehranIran
  2. 2.Esfahan University of Medical SciencesEsfahanIran

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